Compressor inlet valve actuating mechanism



COMPRESSOR INLET VALVE ACTUATING MECHANISM Filed April 14, 1950INVENTOR.

AL ED N. G TAFSON (2 zg' TTORN S.

Patented Jan. 26, 1954 UNITED STATES PATENT erric-E 2 667,299 ooMPa-Es-soa -'IN LET vALv-E AoT Armo M A IS Alfre r fiustafson, :West.Chester, Ra assisnor o S hran m .Ine W )Qhester; Fa a po norat nof Rnnsylvan Application April 14, 1950, Serial No.-155;968

(Cl. 239x30) 3 Claims. 1

This invention relates to valve assemhlies fo compressors andparticularly to valve assemb ies for such compressors as are provided.by the 1693-? version of the parts of an internal combust engine.

Compressors of reciprocating piston type may he provided by theconversion of {the valve arrangement of what may be gbasicallyconsidered an internal combustion engine, :In some casesall of thecylinders of anensine may 'b so conv r ed :to compr s cyl der in whichease th relt mpr so i driv n by an ther en n o mo or alte na vely, on ysome o the cyl ns of a mu i-e linder n ine may b so eo.n yerted s that ac mbinat on ensine e m nessor e u In a y ve t, th c nve sion i adva taeous t h manu a tu er i that e ma or pa f m essors n e ines ma e subst iv i e t c with the or re e suf e i f m th engine o ly the matt of tvalve assemblies.

In my Patent ,2,l,O,860, dated June 6, 1939, there is llu tra d a ers ofor a L head type of engine to a compressor, the conversion beingpossible forall of the cylinders or only some of them as just indicated.This patent shows the arrangement of both inlet and dis.- charge valvesand shows also the provisions for unloading by maintaining the inletvalve cont nu sly p n whe the p ess the rece ver reaches somepredetermined set value. Consid,- ering fi t th inlet val e sse b y fthe p tent, the inlet valve, opening npwardly, may be limited in itsopening movement qpite readily by enga em w t a t o th n osineshelarrangement, however, is not practical in a valve-in-head type ofcompressor that the clearance between the inlet valve and its cont-e.-sponding piston is maintained at a minimum. accordance with the presentinvention provision is made for the proper unloading control of an inletvalve in a 'valve-inhead type of engine. Du n the unl adin p d th camcont nues to reciprocate the inlet valve but its range of movement ischanged so that it reoiprocatesin a cont nu us. y o pos t Dnrine h iloaded period air flows inwardly and outwardly past the inlet valvewithout the production of any substantial compression in the q 1y ,i I1=1- I at in th result the am follower to h inlet valve i ef e t e nated- The invention also relates to improvements in the discharge valveassembly. lnmy patent the discharge valve assembly is :held position bya set screw, which arrangement :has various w.disa vantase particularlyin that it is oimcult for an'unslgilled operator to set the set screwproperly :to Gn ure a pr per operatin os of the discharge valveassembly. In accordance with the present invention an improvedarrangement $101 and op ration, will :become apparent af. the Q1t19Wilg' description read in conjunction with he accompanying drawing, inwhich the figure illustrates in fragmentary vertical section the valveassemblies associated with a single cylinder of the compressor, togetherwith the poet-ml arrangements for unloading the inlet va ve- Eorsimplicity of description the invention will he described as applied toa in l yl n r, it being understood, of .course, that duplicate ar- ;1anse me ts of the valve assemblies will "be proid d QQnilmct-i n withall of the cylinders if 3:11:91 the cylinders of a pa ul unit arePIQSSOI cylinders. or will be applied to some of the cylinders which areutilized for compression ;1n; a unit which is in part engine and in part@QHJDIQfiSQ "Iheey 'nderlolockfl is provided with a cylinder 4 in wh chreoiprocatesthe piston 6. The cylinder is closed by the cylinder head 8which is secured to the block with interposition of the #51 84 aske :19.inlet valve l2 seats at M and uid d through -:a stem :g i l6 b in ur edupward y toward seate o tion :by a spring [8. The inlet air passage isindicated .at 13. Thhficfi 210 carr es ocker arm .22 whi h engages th rer o the va e stem, anais provided with an adjustable screw 2.4 engagingr p er end o the pos rod 2,6, the lower lend 2!! of which i rece ed asocke i a mean ,slidahle ina io lfnder AO- Ihe isto 30 is p ovi ed ,W'i'h a sk t .32 harms opf loss .34 therein. hi snrt a; ine the bore 3; ii albw'r piston 36 which is also mounted in the cylinder 49 As indited-in dotted lines the iow r nliibf the here as is closed. The lowerpiston as is acted upon by the cam 42 corresponding thereto on the camshaft 44. Under operating conditions the upper end of the piston 36engages the piston 39 so that they operate as a unit under the action ofcorresponding cam 42 to produce normal opening movements of the inletvalve l2. A port 46 in the'cylinder it communicates with a groove takeplace. As will be evident from the construction illustrated theintroduction of compressed air through the port 36 will force thepistons 30 and 36 apart. Their-relative movement is limited'by thepresence of a splitring 52 located in a groove 54 in the interior wallof the bore 38, the ring 52 being engageable by the'skirt 32 upon itsupward movement. It may be noted that when any longitudinal movements ofthe two pistons considered together, i. e., the two pistons are free toassume any positions in the cylinder 0 dictated by the spring 18 and thecam 42. The

, result accordingly is merely that of elongation of the connectionsbetween the cam Q2 and the valve I2, with the result that the valvecontinues to reciprocate under the action of the cam but its range ofmovement is lowered below its normal operating range so that it remainsopen at all times during the period of unloading.

The location of the split ring 52 in position is effected by the actionof an annular shoulder 56 on the piston 30. The ring 52 is compressed inthe space below the shoulder 58 and it and piston 30 are then enteredinto the bore 38 in the piston 35. As insertion takes place the ring ispushed inwardly in the bore 38 and eventually provided in the member 62.\Slidably mounted on the pin 53 is a member it provided with axiallyextending openings 12. A spring i l forces the member 19 downwardly andis backed up by a horseshoe-shaped member '38 which is received in asocket it in the cap 30 which is bolted to the top of the cylinder headwith interposition of a gasket 82 to form a closure for the dischargechamber 84. A spring 85 received in an annular groove in the memberflfiholds downwardly a valve ring 88 to cover the openings 63 whichcommunicate with the cylinder space above the piston. The spring 85 isefiectively weaker than the strong spring i l so that compression of airin the upper end of the cylinder will lift the valve ring 88 rather thanthe member 52.

The discharge valve assembly just described has various advantages. Itwill be evident that due to the mounting through the pin 58 the member62 is free to adjust itself accurately to its seat. Furthermore, theentire discharge valve assembly is enclosed below the cap $9 with noprojecting set screw or the like requiring special sealing againstleakage of compressed air. The spring M may be so initially chosen as tothe skirt 32 engages the ring 52 the compressed air between the pistonsis ineifective to produce 4 exert a proper seating pressure onthe'member 62 with the result that an inexperienced person cannot damagethe assembly in putting it in place after its removal.

It may be noted that except in starting up the compressor the chamber 83 will have a pressure which is not substantially less than thepressure,

in the cylinder 5. Accordingly, even if the valve ring 88 did notfunction properly it is quite unlikely that the member 62 would beraised from its seat. The spring 14, of course, will be a quite strongone in any event to insure against v accidental unseating of member 52.

The operations or, the valve assemblies will already be clear from theforegoing. As stated,

unloading is effected by the maintenance of the inlet valve 12 in openposition after the pressure in'th'e receiver exceeds a predeterminedvalue, and this unloading results even though the valve it iscontinuously reciprocated in its lower range by the action of the cam42.

The discharge valve ring 88, of course, opens, whenever the pressure inthe cylinder exceeds by some predetermined amount, depending on thespring 96, the pressureinthe chamber M which is connected to the airreceiver.

What is claimed is:

1. In a compressor including a piston reciprocating in a cylinder and anexhaust valve assembly for said cylinder, an inlet valve operativelyassociated with said cylinder, a seat for the inlet valve, a springacting on said inlet valve to seat said valve, a cam shaft, a camcarried by said shaft, and'means operatively connecting said cam andsaid inlet valve to produce unseating motion of said inlet valve inresponse to rotation of said cam, said connecting means including meansproviding a cylinder, a pair of relatively movable pistons withinthecylinder provided with interengaging means to limit separationthereof, and means for introducing compressed fluid between said pistonsto separate them and so effectively to elongate said connecting meansbetween said cam and said inlet'valve to produce unseating motion of thevalve by the cam in which the valve remains unseated throughout therange of movement of the cam.

2. In a compressor of the valve-in-head type 'including a pistonreciprocating in a cylinder and an exhaust valve assembly for saidcylinder, an inlet valve operatively associated with said cylinder, aseat for the inlet valve, a spring acting on said inlet valve to seatsaid valve, a cam shaft, a cam carried by said shaft, and meansoperatively connecting said cam and said inlet valve to produceunseating motion of said inlet valve in response to rotation of saidcam, said connecting means including a rocker arm and means providing acylinder, a pair of relatively movable pistons within the cylinderprovided with interengaging means to limit separation thereof, and meansfor introducing compressed fluid between said pistons to separate themand so effectively to elongate said connecting means between said camand said inlet valve to produce unseating motion of the valve by the camin which the valve remains unseated throughout the range of movement ofthe cam.

3. In a compressor including a piston reciproeating in a cylinder and anexhaust valve assembly for said cylinder, an inlet valve operativelyassociated with said cylinder, a seat for the inlet valve, a springacting on said inlet valve to seat said valve, a cam shaft, a camcarried by said shaft, and means operatively connecting said 5d cam andsaid inlet valve to produce unseating motion of said inlet valve inresponse to rotation of said cam, said connecting means including meansproviding a cylinder, a pair of relatively movable pistons within thecylinder provided with interengaging means to limit separation thereof,said interengaging means including a skirt on one piston and a ringlocated in an interior groove in the other and engageable by said skirt,and means for introducing compressed fluid between said pistons toseparate them and so efiectively to elongate said connecting meansbetween said cam and said inlet valve to produce References Cited in thefile of this patent UNITED STATES PATENTS Number Name Date 1,649,897Halvorsen Nov. 22, 1927 1,939,801 Wells Dec. 19, 1933 2,161,828Lamberton June 13, 1939 2,192,538 Christensen 1 Mar. 5, 1940

